Link degradation cause indication for multi-TRP reception

Abstract

The embodiment of the invention relates to equipment, a method, a device and a computer readable storage medium for link degradation reason indication for multi-TRP reception. In one method, a terminal device receives a first data transmission from a first network device. The terminal device receives a second data transmission from a second network device. The first data transmission and the second data transmission are based on the same control information. The terminal device transmits cause information to one of the first network device or the second network device, the cause information indicating a cause of relative link degradation or absolute link degradation associated with at least one of the first data transmission or the second data transmission. In this manner, the network may be notified that a link associated with the network device causes degradation.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Indian Provisional Application No. 202341033646, filed on May 12, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] Various exemplary embodiments of this disclosure generally relate to the telecommunications field, and more particularly to methods, apparatus, devices, and computer-readable storage media for indicating link degradation causes for multiple transmission and reception points (TRPs). Background Technology

[0004] In some communication systems, such as New Radio (NR) systems, Multiple-Input Multiple-Output (MIMO) is supported. For example, a terminal device can perform multi-layer downlink MIMO, such as Layer 4, with simultaneous reception from different directions. In some mechanisms, a cell, such as an NR cell, may include one or more Terminal Reception Points (TRPs). TRPs within the same cell have cell-specific common synchronization signals or physical broadcast channel (SS / PBCH) blocks. In multiple-TRP (multi-TRP) operations, it has been proposed that the serving cell can schedule terminal devices, such as User Equipment (UE), from two TRPs. This multiple-TRP provides better coverage, reliability, and data rate for data transmission. For example, multiple downlink (DL) data transmissions can be performed using multiple TRPs. In other words, a terminal device can receive multiple-TRP receptions. Enhancements to multiple-TRP reception are needed. Summary of the Invention

[0005] In a first aspect of this disclosure, an apparatus is provided. The apparatus includes at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive a first data transmission from a first network device; receive a second data transmission from a second network device, the first data transmission and the second data transmission being based on the same control information; and send cause information to one of the first network device or the second network device, the cause information indicating a cause for relative link degradation or absolute link degradation associated with at least one of the first data transmission or the second data transmission.

[0006] In a second aspect of the disclosure, an apparatus is provided. The apparatus includes at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a terminal device, a first data transmission, the first data transmission and a second data transmission being based on a same control information, the second data transmission being transmitted from a network device to the terminal device; and receive, from the terminal device, cause information, the cause information indicating a cause of a relative link degradation or an absolute link degradation associated with at least one of the apparatus or the network device.

[0007] In a third aspect of the disclosure, a method is provided. The method includes: receiving, at a terminal device, a first data transmission from a first network device; receiving a second data transmission from a second network device, the first data transmission and the second data transmission being based on a same control information; and transmitting, to one of the first network device or the second network device, cause information, the cause information indicating a cause of a relative link degradation or an absolute link degradation associated with at least one of the first data transmission or the second data transmission.

[0008] In a fourth aspect of the disclosure, a method is provided. The method includes: transmitting, from a network device, a first data transmission to a terminal device, the first data transmission and a second data transmission being based on a same control information, the second data transmission being transmitted from another network device to the terminal device; and receiving, from the terminal device, cause information, the cause information indicating a cause of a relative link degradation or an absolute link degradation associated with at least one of the network device or the another network device.

[0009] In a fifth aspect of the disclosure, an apparatus is provided. The apparatus includes means for receiving a first data transmission from a first network device; means for receiving a second data transmission from a second network device, the first data transmission and the second data transmission being based on a same control information; and means for transmitting, to one of the first network device or the second network device, cause information, the cause information indicating a cause of a relative link degradation or an absolute link degradation associated with at least one of the first data transmission or the second data transmission.

[0010] In a sixth aspect of the disclosure, an apparatus is provided. Means for transmitting, to a terminal device, a first data transmission, the first data transmission and a second data transmission being based on a same control information, the second data transmission being transmitted from a network device to the terminal device; and means for receiving, from the terminal device, cause information, the cause information indicating a cause of a relative or absolute link degradation associated with at least one of the apparatus or the network device.

[0011] In a seventh aspect of the disclosure, a computer readable medium is provided. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

[0012] In an eighth aspect of the disclosure, a computer readable medium is provided. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

[0013] It should be understood that the summary is not intended to identify key or essential features of embodiments of the disclosure, nor is it intended to limit the scope of the disclosure. Other features of the disclosure will be readily apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0014] Some example embodiments will now be described with reference to the drawings, in which:

[0015] FIG. 1A An example communication environment in which example embodiments of the disclosure can be implemented is shown;

[0016] FIG. 1B An example terminal device in an example communication environment is shown;

[0017] FIG. 1C An example cell area is shown, showing a signal to interference plus noise ratio (SINR) distribution;

[0018] FIG. 2 An example signaling flow for link degradation cause indication according to some example embodiments of the disclosure is shown;

[0019] FIG. 3 An example signaling flow of an RRC message according to some example embodiments of the disclosure is shown;

[0020] FIG. 4 An example diagram showing a channel state information (CSI) reference signal (RS) periodicity and a CSI reporting periodicity according to some example embodiments of the disclosure is shown;

[0021] FIG. 5 A flow diagram of a method implemented at a terminal device according to some example embodiments of the disclosure is illustrated;

[0022] FIG. 6 A flow diagram illustrating a method implemented at a network device, in accordance with some example embodiments of the present disclosure, is shown;

[0023] FIG. 7 A simplified block diagram of a device suitable for implementing example embodiments of the present disclosure is shown; and

[0024] FIG. 8 A block diagram of an example computer readable medium, in accordance with some example embodiments of the present disclosure, is shown.

[0025] In all of the drawings, like or similar reference numerals are used to refer to like or similar elements throughout different views. DETAILED DESCRIPTION

[0026] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described for illustrative purposes only and help the understanding of and enablement of the present disclosure by those skilled in the art, without implying any limitation on the scope of the present disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0027] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0028] Reference throughout this disclosure to “one embodiment”, “an embodiment”, “example embodiment” or similar terms means that a described embodiment might include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Furthermore, these terms are not necessarily referring to the same embodiment. Additionally, where a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of those skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0029] It should be understood that although the terms “first”, “second”… etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed terms.

[0030] As used herein, “at least one of ” and “one or more of ” and similar phrases, where the list of two or more elements is preceded by “and” or “or”, means that at least any one of the listed elements can be present, or at least any two or more of the listed elements can be present, or at least all of the listed elements can be present.

[0031] As used herein, unless expressly stated otherwise, performing a step “in response to” A does not indicate that the step is performed immediately following the occurrence of “A” and can include one or more intervening steps.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including,” when used herein, specify the presence of stated features, elements and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0033] As used in this application, the term “circuitry” can refer to one or more or all of the following:

[0034] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[0035] (b) combinations of hardware circuits and software, such as (as applicable):

[0036] (i) combinations of analog and / or digital hardware circuit(s) with software / firmware and

[0037] (ii) combinations of hardware state machines with software, including digital signal processors), software, and memory that work together to cause an apparatus, such as a mobile phone or server, to perform various functions and

[0038] (c) hardware circuit(s) and / or processor(s) (e.g., a microprocessor or a portion thereof) that require software (e.g., firmware) for operation, but software that need not be present when it is not needed for operation.

[0039] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application the term circuitry also covers an implementation that is at least one integrated circuit or a portion thereof, and / or that is a portion of an application specific integrated circuit. As a further example, as used in this application the term circuitry also covers a

[0040] As used herein, the term “communication network” refers to a network that follows any appropriate communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT), etc. Further, communication between terminal devices and network devices in a communication network can be performed according to any suitable generation communication protocol, including but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), sixth generation (6G) communication protocols, and / or any other protocols that are currently known or developed in the future. Embodiments of the present disclosure can be applied to various communication systems. In consideration of the rapid development of communication, there will of course also be future types of communication technology and systems that can be used to implement the present disclosure. It should not be seen as limiting the scope of the present disclosure to only the aforesaid systems.

[0041] As used herein, the term “network device” refers to a node in a communication network via which terminal devices access the network and receive services from the network. Depending on the terminology used, the network device can refer to a base station (BS) or an access point (AP), e.g., a NodeB (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also known as gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, an integrated access and backhaul (IAB) node, a low power node (such as a femto, pico, non-terrestrial network (NTN) or non-terrestrial network device (such as satellite network devices, low earth orbit (LEO) satellites, and geosynchronous earth orbit (GEO) satellites), a flying aircraft network device, etc. In some example embodiments, a radio access network (RAN) split architecture includes a centralized unit (CU) and a distributed unit (DU) at an IAB donor node. An IAB node includes a mobile terminal (IAB-MT) part that behaves like a UE towards a parent node, and a DU part of the IAB node that behaves like a base station towards a next-hop IAB node. In some example embodiments, a network device can refer to a TRP.

[0042] The term “terminal device” refers to any terminal device capable of wireless communication. By way of example, and without limitation, a terminal device can also be referred to as a communication device, user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). A terminal device can include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over Internet Protocol (VoIP) phone, a wireless local loop phone, a tablet, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device, such as a digital camera, a game terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a USB

[0043] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as a terminal device and a network device, such as a resource in a time domain, a resource in a frequency domain, a resource in a spatial domain, a resource in a code domain, or any other combination of time, frequency, spatial, and / or code domain resources that enable communication, etc. Hereinafter, unless explicitly stated, resources in both the frequency and time domains will be used as examples of transmission resources for describing some example embodiments of the present disclosure. Note that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0044] As described above, in some communication systems, multiple downlink (DL) data transmissions can be performed by multiple TRPs. In other words, a terminal device can receive multi-TRP reception via multiple layers. As used herein, the term “multiple DL reception” can also be referred to as multi-reception (Rx) chain DL reception. For NR frequency range (FR) 2, 4-layer DL MIMO has been proposed for simultaneous reception at a terminal device from two different directions. However, the behavior of a terminal device for multiple DL reception has not been specified when TCI states are not supported. For example, if a terminal device cannot receive on dual-TCI states simultaneously, the behavior of the terminal device needs to be specified. For another example, a terminal device can not support two configured target TCI states simultaneously.

[0045] In some scenarios, in multi-TRP operation, a network, such as a serving cell, schedules a terminal device from two TRPs. In some mechanisms, a single DCI (s-DCI) can be used to schedule multi-TRP PDSCH transmission. In single-DCI mode, a terminal device is scheduled by the same DCI for both TRPs transmitted from one of the two TRPs. Control of uplink and downlink operation can be done by the physical layer and the medium access control (MAC) layer within the configuration provided by the radio resource control (RRC) layer. In single-DCI mode, different TRPs can have different channel conditions or link conditions. However, a terminal device can experience an unfavorable radio condition on one of the received layers due to blockage, fading, power imbalance, etc. Such an unfavorable radio condition can result in a fading of one layer relative to the other. That is, the weaker layer dominates, thereby limiting the actual throughput that the terminal device can achieve.

[0046] There are practical scenarios in which the throughput gain from multi-TRP transmission can be negligible or can even be worse compared to a single-TRP transmission scenario. That is, a multi-Rx multi-panel terminal device receiving two transmissions via s-DCI can experience a performance degradation caused by one of the two simultaneously active links. In such a situation, it would be beneficial for the terminal device to receive from a single direction or use another beam pair for multi-Rx reception. However, the network makes the decision to use another beam pair or to switch the terminal device to single-Rx operation. The terminal device cannot inform the network of such a link degradation. Instead, the network will only know of the performance degradation until the block error rate (BLER) is exceeded and a link failure is declared. That is, the network cannot be informed of the degradation, and therefore, it cannot decide to use another beam pair or to switch the terminal device to single-Rx operation in such a degradation situation.

[0047] According to some example embodiments of the present disclosure, a solution for link degradation cause indication for multi-TRP reception is proposed. In the solution, a terminal device receives a first data transmission from a first network device, such as a first TRP. The terminal device receives a second data transmission from a second network device, such as a second TRP. The first data transmission and the second data transmission are based on a same control information, such as s-DCI from one of the first network device or the second network device. The terminal device sends cause information to one of the first network device or the second network device. The cause information indicates a cause of a relative link degradation or an absolute link degradation associated with at least one of the first data transmission or the second data transmission.

[0048] In this way, the network can be informed that the link associated with the corresponding network device causes degradation when the terminal device receives multiple TRPs.

[0049] The principles and implementations of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0050] FIG. 1A An example communication environment 100 in which example embodiments of the present disclosure can be implemented is shown. In the communication environment 100, multiple communication devices including a terminal device 110, a network device 120-1, and a network device 120-2 can communicate with each other. As used herein, the network device 120-1 and the network device 120-2 can be collectively referred to as “network devices 120” or individually as “network device 120”. In some example embodiments, the network devices 120 can be TRPs.

[0051] In FIG. 1A In an example, the network devices 120 can serve the terminal device 110. A service area of the network devices 120 can be referred to as a cell (not shown). The network device 120-1 and the network device 120-2 can be located in the same cell serving the terminal device 110.

[0052] It should be understood that FIG. 1A The multiple devices and their connections shown in FIG. 1 are for illustrative purposes only and are not intended to suggest any limitation as to the scope of use or functionality of the example embodiments of the present disclosure. The communication environment 100 can include any suitable number of devices configured to implement the example embodiments of the present disclosure. Although not shown, it should be understood that one or more additional devices can be located in the same cell as the network devices 120-1 and 120-2. Note that although shown as network devices, the network devices 120 can be another device other than network devices. Although shown as a terminal device, the terminal device 110 can be a device other than a terminal device.

[0053] In some example embodiments, a link from a network device 120 to a terminal device 110 is referred to as a DL, and a link from a terminal device 110 to a network device 120 is referred to as a UL. In the DL, the network device 120 is a transmitting (TX) device (or transmitter), and the terminal device 110 is a receiving (RX) device (or receiver). In the UL, the terminal device 110 is a TX device (or transmitter), and the network device 120 is an RX device (or receiver). Likewise, a link from a network device 140 to a terminal device 130 is referred to as a DL, and a link from a terminal device 130 to a network device 140 is referred to as a UL. In the DL, the network device 140 is a TX device (or transmitter), and the terminal device 130 is an RX device (or receiver). In the UL, the terminal device 130 is a TX device (or transmitter), and the network device 140 is an RX device (or receiver).

[0054] Communications in the communication environment 100 can be implemented according to any suitable communication protocol, including but not limited to first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), fifth generation (5G), sixth generation (6G), and / or the like cellular communication protocols, wireless local area network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol that is currently known or that will be developed in the future. Moreover, communications can utilize any suitable wireless communication techniques, including but not limited to: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplexing (FDD), time division duplexing (TDD), multiple-input multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and / or any other techniques that are currently known or that will be developed in the future.

[0055] In some example embodiments, both the network device 120-1 and the network device 120-2 can transmit DL data transmissions to the terminal device 110. For example, the network device 120-1 can transmit a first data transmission 134 to the terminal device 110. The network device 120-2 can transmit a second data transmission 136 to the terminal device 110. The data transmissions from the network device 120-1 and the network device 120-2 can be scheduled by a single downlink control information (DCI) (s-DCI). For example, the network device 120-1 can transmit a DCI 132 to the terminal device 110. The DCI 132 can schedule the first data transmission 134 and the second data transmission 136.

[0056] In some example embodiments, the first data transmission 134 is monitored based on a first reference signal (RS) such as a first quasi co-location (QCL) Type D RS. The second data transmission 136 is monitored based on a second RS such as a second QCL Type D RS. In a frequency range (FR) 2, such as FR2-1, simultaneous DL reception with two different QCL Type D RS can be performed on a single component carrier with up to 4 layers of DL MIMO. Radio frequency (RF) requirements, such as spherical coverage requirements, can be specified for devices with simultaneous reception from different directions with different QCL Type D RS. For example, the spherical coverage requirement for reception from a single direction will be maintained. PC3 will be prioritized, with other power classes considered after PC3. Radio resource management (RRM) requirements can be enhanced for such DL reception. For example, measurement relay requirements, radio link monitoring and beam failure detection requirements, scheduling or measurement restrictions, TCI state switching delay with dual TCI can be specified.

[0057] Several requirements can be used for enhanced FR2-1 terminal devices with simultaneous DL reception from different directions with different QCL Type D RS on a single component carrier. For example, terminal device demodulation requirements and performance requirements can be specified for enhanced FR2-1 terminal devices that support up to 4 DL MIMO layers with dual TCI using different QCL Type D on a single component carrier. In addition, CSI requirements can be specified to support up to 4 layers with 2 TCIs and Rel-17 m-TRP Type I codebook. After defining single carrier requirements, extensions of the requirements to cover intra-band carrier aggregation (CA) can be considered.

[0058] For the case of dual TCI demodulation requirements, it can focus on terminal devices such as UEs that support the “simultaneousReceptionDiffTypeD-r16” UE capability. For 2 or 4 layer downlink MIMO reception, it can focus on UEs that support the basic m-TRP CSI reporting capability (FG23-7-1 / 1b of NR FeMIMO).

[0059] Alternatively, in some example embodiments, the data transmissions from network device 120-1 and network device 120-2 can be scheduled by multiple DCIs (m-DCI). For example, network device 120-1 can send a DCI to terminal device 110 to schedule a data transmission from network device 120-1 to terminal device 110. Network device 120-2 can send another DCI (not shown) to terminal device 110 to schedule a data transmission from network device 120-2 to terminal device 110.

[0060] In some example embodiments, the terminal device 110 can support s-DCI scheduled data reception capability or m-DCI scheduled data reception capability or both, depending on the implementation of the terminal device 110. FIG. 1B An example implementation of the terminal device 110 is shown. The terminal device 110 can be a device with multiple receive (RX) capability. For example, the terminal device 110 can include RX chain 142 and RX chain 144. Multiple antenna arrays 132, 134, 136, and 138 (also referred to as antenna panels or antenna modules) are equipped at different locations, for example, different sides of the terminal device 110. These antenna arrays 132, 134, 136, and 138 enable the terminal device 110 to receive signals from different directions simultaneously.

[0061] Reference has been made to FIG. 1A An example implementation of the terminal device 110 is described. It should be appreciated that FIG. 1B The number or location of RX chains and the number or location of antenna arrays shown in FIG. 1 are for illustrative purposes only and are not meant to imply any limitation. Any suitable implementation of the terminal device 110 can be applied.

[0062] In some example embodiments, a modulation coding scheme (MCS) can be selected based on channel conditions. The MCS can affect the achievable throughput. FIG. 1C An example cell area of a single network device 120 is shown, which shows a SINR distribution 170. If the terminal device 110 is located in different areas around the network device 120, different MCSs can be selected based on the corresponding SINR distribution 170. For example, if the terminal device 110 is located within area 172, the conditions of the radio link associated with the network device 120 are good, a high level of efficiency modulation scheme such as 256 quadrature amplitude modulation (QAM) can be applied. A small amount of error correction can be involved. Such a modulation scheme can give high data throughput on the radio channel.

[0063] If the terminal device 110 is located outside of area 172 and within area 174, the conditions of the radio link are lower than those of area 172, a low or medium level of efficiency modulation scheme, for example, 64 QAM can be applied. If the terminal device 110 is located outside of area 174 and within area 176, the conditions of the radio channel are poor, a low level of efficiency modulation scheme such as quadrature phase shift keying (QPSK) can be applied. In addition, the amount of error correction increases in this case. The data throughput will drop significantly. By adapting the link, for example, adapting the transmission settings based on the radio channel conditions, the system capacity, peak data rate, and coverage reliability can be improved.

[0064] As described above, in some communication systems, there is a need to specify the behavior of a terminal device when TCI states are not supported. For multiple DL receptions scheduled by a single DCI, different TRPs can have different channel conditions or link conditions. The terminal device can experience an unfavorable radio condition on one of the reception layers due to blockage, fading, power imbalance, etc. Such an unfavorable radio condition can result in a degradation of one layer relative to another. That is, the weaker layer dominates, thereby limiting the actual throughput that the terminal device can achieve.

[0065] In one example, the terminal device can experience good channel conditions on a first DL channel such as a first physical downlink shared channel (PDSCH) of a first TRP and unfavorable conditions on a second DL channel such as a second PDSCH of a second TRP. In this case, the first link of the first TRP and the second link of the second TRP can both be good enough to support multiple Rx of the terminal device. However, the first link is much better than the second link. For example, the optimal modulation scheme of the first TRP can be 64QAM, while the optimal modulation scheme of the second TRP can be 4QAM. However, due to the s-DCI operation mode, the poorer link performance becomes the limiting factor and the MCS reported to the network will be only 4QAM.

[0066] In this case, 2 bits will be transmitted from each TRP through the first PDSCH or the second PDSCH using 4QAM symbols per channel usage. That is, a 4-bit per channel usage transmission can be performed. However, in this case, if the terminal device determines that multiple Rx (M-RX) with existing beams is not the preferred solution, the terminal device can indicate to the network which link is relatively poor.

[0067] Conversely, if the network switches the terminal device to single Rx with only the first TRP link, which has 64QAM as the best modulation at that point in time, and if the best modulation of 64QAM can be applied, 6 bits per channel usage can be received in the single Rx mode compared to 4 bits per channel usage in the multiple Rx case. That is, in this case, better throughput performance can be achieved by using single Rx instead of multiple Rx.

[0068] However, in the s-DCI mode, due to the unavailability of independent link adaptation for the two activated links, the MCS of the weaker link (the second PDSCH of the second TRP in the above example) will be applied to both the first PDSCH and the second PDSCH. In other words, in the s-DCI mode, due to the unavailability of independent link adaptation, the first PDSCH cannot use the optimal modulation scheme. This will result in a decrease in overall throughput.

[0069] In another scenario, a terminal device can receive from a first TRP and a second TRP only when the angle of arrival (AoA) is such that the DL signals associated with each TRP are received on different antenna modules. At a first time instance, the terminal device reports that it can receive from the first TRP with a first transmission configuration indicator (TCI) and from the second TRP with a second TCI simultaneously. At a second time instance after the first time instance, after the terminal device moves or the AoA of the first TCI and the second TCI rotates, it can have to use the same antenna module to receive all layers. In this case, the terminal device will not be able to receive the first TCI and the second TCI simultaneously, even though they have recently reported that they can be used for simultaneous reception.

[0070] Several examples of degradations in s-DCI scheduled multi-TRP reception have been described, there can be other scenarios of degradations as well. It should be appreciated that there are practical scenarios where the throughput gain from multi-TRP transmission can be negligible or even worse compared to single TRP transmission scenarios. That is, a multi-Rx multi-panel terminal device receiving two transmissions via s-DCI can experience performance degradation caused by one of the two simultaneously active links. Thus, it is more beneficial for the terminal device to receive from a single direction or use another beam pair for multi-Rx reception. However, it is the network that makes the decision to use another beam pair or switch the terminal device to single Rx operation. The terminal device cannot inform the network of such link degradation. Instead, the network will not know of the performance degradation until the block error rate (BLER) exceeds and the link is declared as failed. That is, the network cannot be informed of the degradation and thus cannot decide to use another beam pair or switch the terminal device to single Rx operation in such degradation scenarios.

[0071] To address at least some of the above problems or other potential problems, a solution for link degradation cause indication for multi-TRP reception is proposed. In the solution, a terminal device receives a first data transmission from a first network device, such as a first TRP. The terminal device receives a second data transmission from a second network device, such as a second TRP. The first data transmission and the second data transmission are based on a same control information, such as s-DCI from one of the first network device or the second network device. The terminal device sends cause information to one of the first network device or the second network device. The cause information indicates a cause of a relative link degradation or an absolute link degradation associated with at least one of the first data transmission or the second data transmission. For example, the cause information can indicate a cause of a single link degradation associated with the first network device or the second network device or a combined link degradation associated with the first network device and the second network device.

[0072] In this way, the network can be informed that the link associated with the corresponding network device causes degradation when the terminal device receives from multiple TRPs. Based on the cause information, the network can trigger the terminal device to receive from a single direction or use another beam pair for multi-Rx reception. Data throughput can thus be increased. This solution can thus result in power saving of the terminal device and efficient utilization of network resources.

[0073] FIG. 2 An example signaling flow 200 of link degradation cause information indication is shown in accordance with some example embodiments of the present disclosure. For purposes of discussion, reference will be made to FIG. 1A The signaling flow 200 will be discussed, for example, by using the terminal device 110, the network device 120-1, and the network device 120-2.

[0074] In the description with respect to FIG. 2 It is assumed in the description with respect to

[0075] As shown, the network device 120-1 can transmit (215) control information, such as DCI, to the terminal device 110. The control information can be transmitted (215), for example, by a physical downlink control channel (PDCCH). The terminal device 110 can receive (220) the control information.

[0076] The DCI can include a TCI indication. The TCI indication can indicate two TCI states for data reception. For example, the TCI indication can indicate a first TCI state for a first data transmission, such as a first PDSCH associated with the network device 120-1. Similarly, the TCI indication can indicate a second TCI state for a second data transmission, such as a second PDSCH associated with the network device 120-2. The two TCI states can be determined by the network, such as by a base station. For example, the network can determine the TCI states based on a previous measurement report from the terminal device 110. A TCI state is associated with a beam. Indicating a TCI state means indicating the corresponding beam.

[0077] In some example embodiments, network device 120-1 can transmit (205) a message with a configuration of an aperiodic CSI trigger state to terminal device 110. The message can be in a medium access control element (MAC CE). The message can indicate a CSI report for group-based beam reporting (GBBR), e.g., groupBasedBeamReporting-r17. Terminal device 110 can transmit a measurement report to network device 120-1 for beam selection. For example, a TCI state of network device 120-1 and network device 120-2 can be determined based on the beam selection or the measurement report. Any suitable TCI state determination can be applied.

[0078] As such, a single PDCCH such as s-DCI transmitted (215) from a primary serving network device such as a primary serving TRP can subsequently schedule two PDSCHs with different layers from the primary serving network device and a secondary serving network device.

[0079] Network device 120-1 transmits (225) a first data transmission such as a first PDSCH to terminal device 110. The first data transmission is based on the transmitted (215) control information. Similarly, network device 120-2 transmits (235) a second data transmission such as a second PDSCH to terminal device 110. The second data transmission (235) is also based on the transmitted (215) control information. The second data transmission (235) can overlap with the first data transmission (225). Terminal device 110 receives (230 / 240) the first data transmission / second data transmission.

[0080] The terminal device can monitor a link state. In case of a link degradation, the terminal device can determine (245) cause information based on the monitored link state. Terminal device 110 transmits (250) the cause information to network device 120-1, which receives (255) the cause information. The cause information indicates a cause of a relative link degradation or an absolute link degradation associated with at least one of the first data transmission or the second data transmission. As used herein, the term “link degradation” can refer to a degradation in performance, e.g., a degradation in throughput, due to a link associated with a network device. A relative link degradation can refer to a degradation in performance of a link of a network device relative to another link of another network device. An absolute link degradation can refer to a degradation in performance of a link of a network device relative to a requirement or limit of the link.

[0081] In some example embodiments, the first data transmission is monitored based on a first RS, such as a first quasi co-location (QCL) Type-D RS. The second data transmission is monitored based on a second RS, such as a second QCL Type-D RS. Simultaneous DL reception with two different QCL Type-D RSs can be performed on a single component carrier with up to 4-layer DL MIMO.

[0082] After the TCI states of the network devices 120-1 and 120-2 are indicated, the channel conditions can change due to, for example, movement or rotation of the terminal device 110. The terminal device 110 can send, to the network, cause information of the link degradation caused by such changed channel conditions.

[0083] In one example, the cause of the relative link degradation or the absolute link degradation includes a single link degradation associated with the first data transmission or the second data transmission. In other words, the cause can be that a single one of the first TCI state and the second TCI state experiences the relative degradation or the absolute degradation.

[0084] In some example embodiments, in the embodiments where the cause is a single link degradation associated with one of the first data transmission or the second data transmission, the cause information can further indicate an identifier (ID) of the TCI state associated with the corresponding one of the first data transmission or the second data transmission. For example, if the cause is a single link degradation associated with the first data transmission, such as the first PDSCH, the cause information can further indicate the ID of the first TCI state. By indicating the TCI state ID, the network can know the link that causes the degradation.

[0085] In a further example, the cause of the relative link degradation or the absolute link degradation includes a combined link degradation associated with the first data transmission and the second data transmission. That is, the cause can be that both the first TCI state and the second TCI state experience the degradation.

[0086] In yet another example, the cause of the relative link degradation or the absolute link degradation includes that the first data transmission and the second data transmission cannot be received simultaneously. For example, the cause can be that both the first TCI state and the second TCI state can be received separately, but not simultaneously. For another example, the cause can be that a reception time difference between the network device 120-1 and the network device 120-2 exceeds a threshold. The threshold can be predefined or configured. An example of the threshold can be a maximum reception timing difference (MRTD) limit.

[0087] In some example embodiments, the terminal device 110 can send (250) the cause information to the network device 120-1 if at least one of the following conditions is met. The first condition is that a reception time difference between the first data transmission and the second data transmission is greater than a time threshold. The time threshold can be the MRTD supported by the terminal device 110 or any other suitable time threshold. For example, the first condition is met if the reception time difference experienced between a first RS used to monitor the first data transmission (from the network device 120-1) and a second RS used to monitor the second data transmission (from the network device 120-2) exceeds the time threshold. As used herein, the first RS can be referred to as RS#n and the second RS can be referred to as RS#m. m and n are different integers.

[0088] The second condition is that an AoA between the first data transmission and the second data transmission is less than a threshold angle. The threshold angle can be the minimum angular separation supported by the terminal device 110. For example, the second condition is met if the AoA between RS#n and RS#m is less than the threshold angle.

[0089] The third condition is that a difference between a first value of a measurement result of the first data transmission and a second value of a measurement result of the second data transmission is greater than a threshold. As used herein, the threshold can also be referred to as a first threshold. For example, the third condition is met if a difference between reference signal received power (RSRP) level measurements from RS#n and RS#m exceeds the threshold, e.g., X dB (X is an integer).

[0090] The fourth condition is that a combined rank of the first data transmission and the second data transmission is less than at least one of a first rank of the first data transmission or a second rank of the second data transmission. For example, the fourth condition is met if the combined rank when considering RS#n and RS#m is less than a rank achievable from RS#n or RS#m.

[0091] The terminal device 110 can send (250) the cause information to the network device 120-1 if at least one of the above conditions is met, it should be understood that the above conditions for sending the cause information are for illustrative purposes only and are not meant to imply any limitation. Any other suitable condition can be applied. The scope of the present disclosure is not limited thereto.

[0092] In some example embodiments, the terminal device 110 can determine (245) the cause information if at least one condition is met. The determined (245) cause information can be sent (250) by the terminal device 110.

[0093] In one example, the terminal device 110 can determine the cause information to be a single degradation based on a difference between a first value of a measurement result of the first data transmission and a second value of a measurement result of the second data transmission exceeding a first threshold, such as the threshold mentioned above. The first threshold can be predefined or configured. For example, the first threshold can be X dB, where X is an integer. If the difference between the first value and the second value exceeds the first threshold, e.g., if the first TCI is X dB lower than the second TCI, the terminal device 110 can determine (245) that the cause information is a single degradation. In such an example, the single degradation is a relative link degradation. The cause information can also indicate the ID of the lower TCI state.

[0094] In a further example, the terminal device 110 can determine the cause information to be a single degradation based on a value of a measurement result of the first data transmission or the second data transmission being less than a second threshold. In yet another example, the terminal device 110 can determine the cause information to be a single degradation based on a block error rate of the first data transmission or the second data transmission being greater than a third threshold. The second threshold and the third threshold can be predefined or configured. For example, if the first TCI or the second TCI experiences an absolute low RSRP value or a high BLER value, the terminal device 110 can determine (245) that the cause information is a single degradation. In such an example, the single degradation is a relative link degradation. The cause information can also indicate the ID of the lower TCI state.

[0095] Examples have been described regarding determining (245) the cause information to be a single link degradation. It should be appreciated that the terminal device 110 can determine (245) the cause information based on other conditions or criteria. In some cases, the terminal device 110 can instead determine (245) that the cause information is a combined link degradation or that the first data transmission and the second data transmission cannot be received simultaneously.

[0096] In this way, if the terminal device 110 experiences a total throughput degradation due to a lower performing link, such as an unfavorable channel condition, the terminal device 110 can inform the network, such as a base station of the network, by signaling the cause information to a network device 120-1, such as a primary serving TRP. The cause information can indicate that simultaneous reception of the current beam pair is no longer optimal or no longer possible. For example, the cause information can indicate that the terminal device is experiencing a throughput degradation due to one of the received links. As another example, the terminal device can inform the network which TRP is transmitting the weaker link. The network can also know the TCI state pair is no longer suitable for simultaneous reception.

[0097] In some example implementations, cause information is included in the Radio Resource Control (RRC) message. For example, the RRC message may be a UE Assistance Information (UAI) message. FIG. 3 An example signaling flow for an RRC message is shown. As shown, one or more RRC (re)configuration messages can be sent / received (310 / 320) between terminal device 110 and network device 120, such as network device 120-1. Terminal device 110 can send a (330) UEAssistanceInformation message to network device 120-1, and network device 120-1 can receive a (340) UEAssistanceInformation message. Terminal device 110 can use the UEAssistanceInformation message to inform the network of its preferences for certain parameters used for power saving, such as indication of overheat assistance, relaxation of radio link monitoring (RLM) measurements, beam fault detection (BFD), etc. The UEAssistanceInformation message can be signaled via signaling radio bearer (SRB) SRB1 or SRB3. The radio link control (RLC)-serving access point (SAP) used for the UEAssistanceInformation message is Acknowledgment Mode (AM). The logical channel used for the UEAssistanceInformation message is the downlink control channel (DCCH). The direction of the UEAssistanceInformation message is from the terminal device to the network.

[0098] In some example embodiments, the UEAssistanceInformation message may include additional information elements for cause information. Examples of UEAssistanceInformation messages are shown in Table 1 below.

[0099] Table 1

[0100]

[0101] In the example UEAssistanceInformation messages in Table 1, the field “sDCI-LinkDegradation” or information elements of the UEAssistanceInformation message indicate cause information. For example, “Cause1-noSimultaneousReception” can indicate that the cause of relative or absolute link degradation is “the first and second data transmissions cannot be received simultaneously.” Another example is “Cause2-SingleLinkDegradation,” which can indicate that the cause of relative or absolute link degradation is “a single link degradation associated with either the first or second data transmission.” For single link degradation cases, the TCI state ID “TCI-stateId” can also be included in the UEAssistanceInformation message. For another example, “Cause3-TwoLinksWithDegradation” can indicate that the cause of relative or absolute link degradation is “a combined link degradation associated with both the first and second data transmissions.”

[0102] Alternatively or additionally, in some example embodiments, cause information may be included in the measurement report. For example, terminal device 110 may wait for the next report instance and include cause information such as the cause and condition of link degradation in the measurement report.

[0103] Examples of measurement reports may include, but are not limited to, Channel State Information (CSI) reports, Layer 1 (L1)-RSRP reports, or group-based measurement reports, such as Layer 1 (L1)-RSRP Group-Based Beam Reports (GBBRs). Measurement reports may include RS pairs that can be simultaneously received by the network. That is, in the measurement report, terminal device 110 can inform the network which are good or optimal beam pairs that it can simultaneously receive.

[0104] FIG. 4 Example diagrams illustrating CSI-RS cycle 410 and CSI report cycle 420 according to some example embodiments of this disclosure are shown. That is, networks such as network devices 120-1 and 120-2 can periodically send CSI-RS to terminal device 110. Terminal device 110 can periodically send CSI reports to networks such as network device 120-1.

[0105] In some example embodiments, terminal device 110 may determine whether the periodicity of a measurement report, such as CSI reporting period 420, is less than a threshold periodicity. The threshold periodicity may be predefined or configured. If the periodicity of the measurement report is less than the threshold periodicity, terminal device 110 may send a measurement report (250) to network device 120-1, which includes cause information.

[0106] Alternatively, if the periodicity of the measurement reports is greater than or equal to a threshold periodicity, the terminal device 110 may send an RRC message, such as a UEAssistanceInformation message, to the network device 120-1. The RRC includes cause information. Including cause information in the measurement reports is particularly beneficial if the periodicity of the measurement reports is relatively small.

[0107] Alternatively or additionally, in some example embodiments, terminal device 110 may determine whether the duration preceding the next measurement report is less than a threshold duration. For example, terminal device 110 may determine whether the duration from the current time instance to the next measurement report is less than a threshold duration. The threshold duration may be predefined or configured. If the duration is less than the threshold duration, terminal device 110 may send a measurement report (250) to network device 120-1. The measurement report includes cause information.

[0108] Alternatively, if the duration is greater than or equal to a threshold duration, the terminal device may send an RRC message, such as a UEAssistationInformation message, to network device 120-1. The RRC includes cause information.

[0109] In this way, cause information can be notified using a periodic reporting mechanism. The inclusion of cause information in the measurement report or the RRC message can be determined based on the periodicity of the measurement report or the duration before the next measurement report. By including cause information in the measurement report or alternatively in the RRC message, it is not necessary to send measurement reports more frequently. That is, the periodicity of the measurement report does not need to be reduced. Therefore, this method of indicating cause information is beneficial for increasing the periodicity of CSI reports. For example, the periodicity of CSI reports, such as a CSI report cycle of 420, can be configured from 4 time slots to up to 320 time slots, or any other suitable time length.

[0110] Maintaining longer periods of measurement reports or CSI reports is advantageous because it reduces the frequency of signaling in the form of CSI reports from terminal devices to networks such as base stations, and it helps maximize the number of terminal devices in the RRC_CONNECTED (RRC_connected) state. On the other hand, it also means that terminal devices will have to wait longer to report changes in radio conditions.

[0111] Not all terminal devices in a cell will experience performance degradation, so having a very short CSI reporting period can be counterproductive. If the CSI reporting period is longer, including cause information in the RRC message may be useful. Terminal devices experiencing any of the conditions listed above can send an RRC message, such as a UEAssistanceInformation message, to the base station.

[0112] If the CSI reporting cycle is short or if a degradation can be tolerated until the next CSI reporting time, it may be useful to include cause information in the measurement report.

[0113] Several example embodiments regarding the inclusion of cause information in RRC messages or measurement reports have been described. It will be understood that including cause information in RRC messages and in measurement reports can be used individually or in combination. Cause information can also be included in any other suitable signaling. The scope of this disclosure is not limited thereto.

[0114] Now return to the reference FIG. 2 As described above, network device 120-1 receives (255) cause information. In some example embodiments, using the cause information, network device 120-1 or the network's base station may perform additional or further actions. For example, if necessary, the network may take further actions based on conditions common to the instance at that time. Examples of further actions may include instructing terminal devices to send additional measurement reports for selecting a new beam pair or a new individual beam.

[0115] In some example embodiments, network device 120-1 may send (280) further control information to terminal device 110 indicating a single TCI state or a pair of TCI states. In this way, a new pair of TCI states or a single TCI state can be activated or indicated. The UE can then switch to another TCI state.

[0116] Specifically, in some example embodiments, in response to receiving cause information, network device 120 may send (260) a measurement report request to terminal device 110 for updating the TCI status of at least one of network devices 120-1 or 120-2. Terminal device 110 may receive (265) the request for the measurement report. For example, the request may be included in a DCI such as DCI format 0_1.

[0117] Terminal device 110 may send (270) a measurement report associated with at least one beam used for reception to network device 120-1. For example, the measurement result may be an updated L1-RSRP report with a suitable beam pair or suitable beam for simultaneous reception. Network device 120-1 may receive (275) a measurement report associated with at least one beam used for reception.

[0118] Network device 120-1 can determine a single TCI state or a pair of TCI states based on a measurement report. For example, if a pair of TCI states or a pair of beams is suitable for simultaneous reception based on a measurement report, network device 120-1 can determine that pair of TCI states. Network device 120-1 can send (280) to terminal device 110 further control information indicating the TCI state pair for network device 120-1 and network device 120-2.

[0119] Alternatively, if no available TCI state pair or beam pair exists for simultaneous reception, network device 120-1 can determine a single TCI state for either network device 120-1 or network device 120-2. In this way, depending on network implementation, services, and general radio conditions, terminal devices can be configured for a single TRP scenario, and resources can be allocated to other terminal devices.

[0120] By activating or indicating a new single TCI state or a new pair of TCI states for the terminal device, power savings for the terminal device and efficient utilization of network resources for the base station can be achieved. For example, in s-DCI deployments, due to the lack of separate link adaptation, the terminal device may not experience higher throughput if one of the received links degrades. The terminal device then simply wastes power and network resources by using two antenna arrays. In this case, it is beneficial for the terminal device to notify the network of the degradation caused by one of the links.

[0121] The network can then select to assign another beam pair to the terminal device based on the latest L1-RSRP measurement report, or simply assign these resources to another terminal device based on the network implementation. It can also configure the terminal device to operate in a single Rx mode if no good beam pair is available.

[0122] It should be understood that the roles of network device 120-1 and network device 120-2 can be interchanged. For example, although... FIG. 2 As shown, terminal device 110 sends cause information (250) to network device 120-1, which sends control information (215) to terminal device 110. However, in some example embodiments, terminal device 110 may send cause information to network device 120-2 instead of network device 120-1. For another example, although as... FIG. 2 As shown, terminal device 110 receives (265) a request from network device 120-1 and sends (270) a measurement report to network device 120-1. However, in some example embodiments, terminal device 110 may receive a request from network device 120-2 and send a measurement report to network device 120-2. The scope of this disclosure is not limited to this aspect.

[0123] FIG. 5 A flowchart of an example method 500 implemented at a terminal device according to some example embodiments of the present disclosure is shown. For discussion purposes, [the following will be discussed]. FIG. 1A Method 500 is described from the perspective of terminal device 110.

[0124] At box 510, terminal device 110 receives first data transmission from a first network device, such as network device 120-1.

[0125] In block 520, terminal device 110 receives a second data transmission from a second network device, such as network device 120-2, wherein the first data transmission and the second data transmission are based on the same control information.

[0126] At box 530, terminal device 110 sends cause information to one of the first network device or the second network device, the cause information indicating the cause of relative link degradation or absolute link degradation associated with at least one of the first data transmissions or the second data transmissions.

[0127] In some example embodiments, the reasons for relative link degradation or absolute link degradation include at least one of the following: single link degradation associated with the first data transmission or the second data transmission, combined link degradation associated with the first data transmission and the second data transmission, or the first data transmission and the second data transmission cannot be received simultaneously.

[0128] In some example embodiments, the cause of relative link degradation or absolute link degradation includes a single link degradation associated with one of the data transmissions in the first data transmission or the second data transmission, and the cause information also indicates an identifier of the Transmission Configuration Indicator (TCI) state associated with the corresponding data transmission in the first data transmission or the second data transmission.

[0129] In some example embodiments, method 500 further includes determining a single link degradation based on at least one of the following: the difference between a first value of a measurement result of a first data transmission and a second value of a measurement result of a second data transmission exceeds a first threshold, the value of a measurement result of the first data transmission or the second data transmission is less than a second threshold, or the block error rate of the first data transmission or the second data transmission is greater than a third threshold.

[0130] In some example embodiments, the cause information includes at least one of the following: a radio resource control message or a measurement report.

[0131] In some example embodiments, method 500 further includes: determining whether the periodicity of the measurement report is less than a threshold periodicity; based on determining that the periodicity of the measurement report is less than the threshold periodicity, sending a measurement report including cause information to at least one of the first network device or the second network device; and based on determining that the periodicity of the measurement report is greater than or equal to the threshold periodicity, sending a radio resource control message including cause information to at least one of the first network device or the second network device.

[0132] In some example embodiments, method 500 further includes: determining whether the duration prior to the next measurement report is less than a threshold duration; based on determining that the duration is less than the threshold duration, sending a measurement report including cause information to at least one of the first network device or the second network device; and based on determining that the duration is greater than or equal to the threshold duration, sending a radio resource control message including cause information to at least one of the first network device or the second network device.

[0133] In some example embodiments, method 500 further includes sending cause information based on determining that at least one of the following conditions is met: a first condition that the reception time difference between the first data transmission and the second data transmission is greater than a fourth threshold; a second condition that the angle of arrival between the first data transmission and the second data transmission is less than a fifth threshold; a third condition that the difference between the first value of the measurement result of the first data transmission and the second value of the measurement result of the second data transmission is greater than a sixth threshold; or a fourth condition that the combined rank of the first data transmission and the second data transmission is less than at least one of the first rank of the first data transmission or the second rank of the second data transmission.

[0134] In some example embodiments, method 500 further includes: receiving control information from one of the first network device or the second network device, indicating a first Transport Configuration Indicator (TCI) state for the first data transmission and a second TCI state for the second data transmission.

[0135] In some example embodiments, method 500 further includes: receiving from one of the first network devices or the second network devices a request for a measurement report for updating the Transmission Configuration Indicator (TCI) status for at least one of the first network devices or the second network devices; and sending the measurement report associated with at least one beam for reception to the corresponding network device of the first network device or the second network device.

[0136] In some example embodiments, method 500 further includes receiving, from one of the first network devices or the second network device, further control information indicating a single TCI state or a pair of TCI states, the single TCI state or the pair of TCI states being determined based on a measurement report.

[0137] In some example embodiments, the first network device includes a first transmission receiving point (TRP), and the second network device includes a second TRP.

[0138] FIG. 6 A flowchart of an example method 600 implemented at a network device according to some example embodiments of the present disclosure is shown. For discussion purposes, [the following will be discussed]. FIG. 1A Method 600 describes the network device 120 from the perspective of network device 120.

[0139] At box 610, network device 120 sends a first data transmission to a terminal device, such as terminal device 110. The first data transmission and the second data transmission are based on the same control information. The second data transmission is sent from another network device to the terminal device.

[0140] At box 620, network device 120 receives cause information from terminal device, which indicates the cause of relative link degradation or absolute link degradation associated with network device or at least one of other network devices.

[0141] In some example embodiments, the reasons for relative link degradation or absolute link degradation include at least one of the following: single link degradation associated with the first data transmission or the second data transmission, combined link degradation associated with the first data transmission and the second data transmission, or the first data transmission and the second data transmission cannot be received simultaneously.

[0142] In some example embodiments, the cause of relative link degradation or absolute link degradation includes a single link degradation associated with one of the data transmissions in the first data transmission or the second data transmission, and the cause information also indicates an identifier of the Transmission Configuration Indicator (TCI) state associated with the corresponding data transmission in the first data transmission or the second data transmission.

[0143] In some example embodiments, a single link degradation is determined based on at least one of the following: the difference between a first value of a measurement result of a first data transmission and a second value of a measurement result of a second data transmission exceeds a first threshold; the value of a measurement result of the first data transmission or the second data transmission is less than a second threshold; or the block error rate of the first data transmission or the second data transmission is greater than a third threshold.

[0144] In some example embodiments, cause information is included in at least one of the following: radio resource control messages or measurement reports.

[0145] In some example embodiments, method 600 further includes sending control information to a terminal device indicating a first Transmission Configuration Indicator (TCI) state for the first data transmission and a second TCI state for the second data transmission.

[0146] In some example embodiments, method 600 further includes: in response to receiving cause information, sending further control information to the terminal device indicating the state of a single Transmission Configuration Indicator (TCI) or a pair of TCI states.

[0147] In some example embodiments, method 600 further includes: in response to receiving cause information, sending a request to a terminal device for updating a measurement report for at least one of the network devices, namely the network device or another network device, of a measurement report for updating the TCI status; receiving from the terminal device a measurement report associated with at least one beam for receiving; determining a single TCI status or a pair of TCI statuses based on the measurement report; and sending further control information to the terminal device indicating the single TCI status for the network device or the pair of TCI statuses for the network device and another network device.

[0148] In some example embodiments, the network device includes a first Transmit Receive Point (TRP), and another network device includes a second TRP.

[0149] In some example embodiments, any of the first means of method 500 can be performed (e.g., FIG. 1A The terminal device 110 in the process may include components for performing the corresponding operations of method 500. These components can be implemented in any suitable form. For example, the components can be implemented in a circuit or software module. The first device can be implemented as... FIG. 1A Terminal device 110 or included in FIG. 1A In terminal device 110.

[0150] In some example embodiments, the first device includes components for receiving a first data transmission from a first network device; components for receiving a second data transmission from a second network device, the first data transmission and the second data transmission being based on the same control information; and components for sending to one of the first network device or the second network device reason information indicating relative link degradation or absolute link degradation associated with at least one of the first data transmissions or the second data transmission.

[0151] In some example embodiments, the reasons for relative link degradation or absolute link degradation include at least one of the following: single link degradation associated with the first data transmission or the second data transmission, combined link degradation associated with the first data transmission and the second data transmission, or the first data transmission and the second data transmission cannot be received simultaneously.

[0152] In some example embodiments, the cause of relative or absolute link degradation includes a single link degradation associated with one of the data transmissions in the first data transmission or the second data transmission, and the cause information also indicates an identifier of the Transmission Configuration Indicator (TCI) state associated with the corresponding data transmission in the first data transmission or the second data transmission.

[0153] In some example embodiments, the first device further includes a component for determining a single link degradation based on at least one of the following: the difference between a first value of a measurement result of a first data transmission and a second value of a measurement result of a second data transmission exceeds a first threshold, the value of a measurement result of the first data transmission or the second data transmission is less than a second threshold, or the block error rate of the first data transmission or the second data transmission is greater than a third threshold.

[0154] In some example embodiments, cause information is included in at least one of the following: radio resource control messages or measurement reports.

[0155] In some example embodiments, the first apparatus further includes: a component for determining whether the periodicity of the measurement report is less than a threshold periodicity; a component for sending a measurement report including cause information to at least one of the first network device or the second network device based on determining that the periodicity of the measurement report is less than the threshold periodicity; and a component for sending a radio resource control message including cause information to at least one of the first network device or the second network device based on determining that the periodicity of the measurement report is greater than or equal to the threshold periodicity.

[0156] In some example embodiments, the first apparatus further includes: components for determining whether the duration prior to the next measurement report is less than a threshold duration; components for sending a measurement report including cause information to at least one of the first network device or the second network device based on the determination that the duration is less than the threshold duration; and components for sending a radio resource control message including cause information to at least one of the first network device or the second network device based on the determination that the duration is greater than or equal to the threshold duration.

[0157] In some example embodiments, the first device further includes a component for transmitting cause information based on determining that at least one of the following conditions is met: a first condition that the reception time difference between the first data transmission and the second data transmission is greater than a fourth threshold; a second condition that the angle of arrival between the first data transmission and the second data transmission is less than a fifth threshold; a third condition that the difference between the first value of the measurement result of the first data transmission and the second value of the measurement result of the second data transmission is greater than a sixth threshold; or a fourth condition that the combined rank of the first data transmission and the second data transmission is less than at least one of the first rank of the first data transmission or the second rank of the second data transmission.

[0158] In some example embodiments, the first apparatus further includes a component for receiving control information from one of the first network devices or the second network devices, indicating a first Transmission Configuration Indicator (TCI) state for first data transmission and a second TCI state for second data transmission.

[0159] In some example embodiments, the first apparatus further includes: components for receiving from one of the first network devices or the second network devices a request for updating a measurement report for updating the Transmission Configuration Indicator (TCI) status for at least one of the first network devices or the second network devices; and components for sending a measurement report associated with at least one beam for reception to the corresponding network device in the first network device or the second network device.

[0160] In some example embodiments, the first device further includes a component for receiving further control information from one of the first network devices or the second network devices, indicating a single TCI state or a pair of TCI states, the single TCI state or the pair of TCI states being determined based on a measurement report.

[0161] In some example embodiments, the first network device includes a first transmission receiving point (TRP), and the second network device includes a second TRP.

[0162] In some example embodiments, the first device further includes components for performing other operations in some example embodiments of method 500 or terminal device 110. In some example embodiments, the components include at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause execution of the first device.

[0163] In some example embodiments, any of the second means of method 600 can be performed (e.g., FIG. 1A The network device 120 in the process may include a component for performing the corresponding operation of method 600. This component can be implemented in any suitable form. For example, the component can be implemented in a circuit or software module. The second device can be implemented as... FIG. 1A Network device 120 or included in FIG. 1A Among the network devices in 120.

[0164] In some example embodiments, the second device includes components for sending a first data transmission to a terminal device, the first data transmission and the second data transmission being based on the same control information, the second data transmission being sent from a network device to the terminal device; and components for receiving cause information from the terminal device, the cause information indicating a cause of relative link degradation or absolute link degradation associated with at least one of the devices or network devices.

[0165] In some example embodiments, the reasons for relative link degradation or absolute link degradation include at least one of the following: single link degradation associated with the first data transmission or the second data transmission, combined link degradation associated with the first data transmission and the second data transmission, or the first data transmission and the second data transmission cannot be received simultaneously.

[0166] In some example embodiments, the cause of relative link degradation or absolute link degradation includes a single link degradation associated with one of the data transmissions in the first data transmission or the second data transmission, and the cause information indicates an identifier of the Transmission Configuration Indicator (TCI) state associated with the corresponding data transmission in the first data transmission or the second data transmission.

[0167] In some example embodiments, a single link degradation is determined based on at least one of the following: the difference between a first value of a measurement result of a first data transmission and a second value of a measurement result of a second data transmission exceeds a first threshold; the value of a measurement result of the first data transmission or the second data transmission is less than a second threshold; or the block error rate of the first data transmission or the second data transmission is greater than a third threshold.

[0168] In some example embodiments, the cause information includes at least one of the following: a radio resource control message or a measurement report.

[0169] In some example embodiments, the second apparatus further includes a component for sending control information to the terminal device indicating a first Transmission Configuration Indicator (TCI) state for the first data transmission and a second TCI state for the second data transmission.

[0170] In some example embodiments, the second apparatus further includes a component for sending further control information indicating a single Transmission Configuration Indicator (TCI) state or a pair of TCI states to a terminal device in response to receiving cause information.

[0171] In some example embodiments, the second apparatus further includes: components for sending a request to a terminal device in response to receiving cause information for updating a measurement report for updating the TCI status of at least one of the apparatus or network devices; components for receiving from the terminal device a measurement report associated with at least one beam for receiving; components for determining a single TCI status or a pair of TCI statuses based on the measurement report; and components for sending further control information to the terminal device indicating a single TCI status for the device or a pair of TCI statuses for the device and the network devices.

[0172] In some example embodiments, the apparatus includes a first transmission receiving point (TRP), and the network device includes a second TRP.

[0173] In some example embodiments, the second means further includes components for performing other operations in some example embodiments of method 600 or network device 120. In some example embodiments, the components include at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second means to perform.

[0174] FIG. 7 This is a simplified block diagram of a device 700 suitable for implementing an example embodiment of the present disclosure. The device 700 can be provided to implement a communication device, such as the terminal device 110 or network device 120 shown in FIG1. ​​As shown, the device 700 includes one or more processors 710, one or more memories 720 coupled to the processors 710, and one or more communication modules 740 coupled to the processors 710.

[0175] Communication module 740 is used for bidirectional communication. Communication module 740 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interface can represent any interface necessary for communication with other network elements. In some example embodiments, communication module 740 may include at least one antenna.

[0176] Processor 710 can be any type suitable for a local technology network and can include one or more of the following: as non-limiting examples, general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. Device 700 can have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock of a synchronous main processor.

[0177] Memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 724, electrically programmable read-only memory (EPROM), flash memory, hard disk, high-density disk (CD), digital video disk (DVD), optical disk, laser disk, and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 722 and other volatile memories that do not persist during power-off periods.

[0178] Computer program 730 includes computer-executable instructions that are executed by an associated processor 710. The instructions of program 730 may include instructions for performing operations / actions of some example embodiments of this disclosure. Program 730 may be stored in memory, such as ROM 724. Processor 710 can perform any suitable actions and processes by loading program 730 into RAM 722.

[0179] An exemplary embodiment of the present invention can be implemented by program 730, such that device 700 can perform as described in reference. FIG. 2 to FIG. 6 Any process of the invention discussed herein. Exemplary embodiments of this disclosure may also be implemented in hardware or through a combination of software and hardware.

[0180] In some example embodiments, program 730 may be tangibly contained in a computer-readable medium, which may be included in device 700 (e.g., in memory 720) or in other storage devices accessible by device 700. Device 700 may load program 730 from the computer-readable medium into RAM 722 for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. As used herein, the term "non-transitory" is a limitation of the medium itself (i.e., tangible, non-signal), as opposed to limitations on the persistence of data storage (e.g., RAM versus ROM).

[0181] FIG. 8 An example of a computer-readable medium 800 is shown, which may be in the form of a CD, DVD, or other optical storage disc. The computer-readable medium 800 has a program 730 stored thereon.

[0182] Generally, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, and others can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are illustrated and described as block diagrams, flowcharts, or other illustrated representations, it should be understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0183] Some exemplary embodiments of this disclosure also provide at least one computer program product tangibly stored on a computer-readable medium, such as a non-transitory computer-readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, which execute in a device on a target physical or virtual processor to perform any of the methods described above. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc., that perform a particular task or implement a particular abstract data type. The functionality of program modules can be combined or split among program modules as required in each embodiment. The machine-executable instructions for program modules can execute within a local or distributed device. In a distributed device, program modules can reside in both local and remote storage media.

[0184] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0185] In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0186] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples of computer-readable storage media will include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable high-density disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0187] Furthermore, although the operations are described in a specific order, this should not be construed as requiring that such operations be performed in the specific order shown or in sequential order, or requiring that all the operations shown be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the foregoing discussion, these details should not be construed as limiting the scope of the invention, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated otherwise, certain features described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated otherwise, the various features described in the context of a single embodiment may also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0188] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as examples of implementing the claims.

Claims

1. An apparatus comprising: At least one processor; as well as At least one memory storing instructions, which, when executed by the at least one processor, cause the device to at least: Receive the first data transmission from the first network device; Receive a second data transmission from a second network device, wherein the first data transmission and the second data transmission are based on the same control information; as well as Send cause information to one of the first network device or the second network device, the cause information indicating the cause of relative link degradation or absolute link degradation associated with at least one of the first data transmission or the second data transmission.

2. The apparatus according to claim 1, wherein, The reasons for the relative link degradation or absolute link degradation include at least one of the following: Degradation of a single link associated with the first data transmission or the second data transmission. Combined link degradation associated with the first data transmission and the second data transmission, or The first data transmission and the second data transmission cannot be received simultaneously.

3. The apparatus according to claim 2, wherein, The reasons for the relative link degradation or absolute link degradation include the single link degradation associated with one of the data transmissions in the first data transmission or the second data transmission, and the reason information further indicates an identifier of the Transmission Configuration Indicator (TCI) status associated with the corresponding data transmission in the first data transmission or the second data transmission.

4. The apparatus according to claim 2 or claim 3, wherein, The device is such that: The degradation of a single link is determined based on at least one of the following: The difference between the first value of the measurement result from the first data transmission and the second value of the measurement result from the second data transmission exceeds a first threshold. The value of the measurement result of the first data transmission or the second data transmission is less than the second threshold, or The block error rate of the first data transmission or the second data transmission is greater than the third threshold.

5. The apparatus according to any one of claims 1-4, wherein, The cause information is included in at least one of the following: Radio resource control messages, or Measurement report.

6. The apparatus according to claim 5, wherein, The device is such that: Determine whether the periodicity of the measurement report is less than the threshold periodicity; Based on the determination that the periodicity of the measurement report is less than the threshold periodicity, the measurement report including the cause information is sent to at least one of the first network device or the second network device; as well as Based on the determination that the periodicity of the measurement report is greater than or equal to the threshold periodicity, the radio resource control message including the cause information is sent to at least one of the first network device or the second network device.

7. The apparatus according to claim 5 or claim 6, wherein, The device is such that: Determine if the duration before the next measurement report is less than the threshold duration; Based on the determination that the duration is less than the threshold duration, the measurement report including the cause information is sent to at least one of the first network device or the second network device; as well as Based on determining that the duration is greater than or equal to the threshold duration, the radio resource control message including the cause information is sent to at least one of the first network device or the second network device.

8. The apparatus according to any one of claims 1-7, wherein, The device is such that: The reason information is sent based on at least one of the following conditions: The first condition is that the reception time difference between the first data transmission and the second data transmission is greater than the fourth threshold. The second condition is that the angle of arrival between the first data transmission and the second data transmission is less than the fifth threshold. The third condition is that the difference between the first value of the measurement result of the first data transmission and the second value of the measurement result of the second data transmission is greater than the sixth threshold, or The fourth condition is that the combined rank of the first data transmission and the second data transmission is less than at least one of the first rank of the first data transmission or the second rank of the second data transmission.

9. The apparatus according to any one of claims 1-8, wherein, The device is such that: The control information is received from one of the first network devices or the second network device, indicating a first Transmission Configuration Indicator (TCI) state for the first data transmission and a second TCI state for the second data transmission.

10. The apparatus according to any one of claims 1-9, wherein, The device is such that: Receive a request from one of the first network devices or the second network devices for updating a measurement report for the Transmission Configuration Indicator (TCI) status of at least one of the first network devices or the second network devices. as well as Send a measurement report associated with at least one beam used for receiving to the corresponding network device in the first network device or the second network device.

11. The apparatus according to claim 10, wherein, The device is such that: Receive further control information from one of the first or second network devices, indicating a single TCI state or a pair of TCI states, the single TCI state or the pair of TCI states being determined based on the measurement report.

12. The apparatus according to any one of claims 1-11, wherein, The first network device includes a first Transmitter Receiver Point (TRP), and the second network device includes a second TRP.

13. An apparatus comprising: At least one processor; as well as At least one memory storing instructions, which, when executed by the at least one processor, cause the device to at least: Sending a first data transmission to a terminal device, wherein the first data transmission and the second data transmission are based on the same control information, and the second data transmission is sent from the network device to the terminal device; as well as Receive cause information from the terminal device, the cause information indicating the cause of relative link degradation or absolute link degradation associated with at least one of the device or the network device.

14. The apparatus according to claim 13, wherein, The reasons for the relative link degradation or absolute link degradation include at least one of the following: Degradation of a single link associated with the first data transmission or the second data transmission. Combined link degradation associated with the first data transmission and the second data transmission, or The first data transmission and the second data transmission cannot be received simultaneously.

15. The apparatus according to claim 14, wherein, The reasons for the relative link degradation or absolute link degradation include the single link degradation associated with one of the data transmissions in the first data transmission or the second data transmission, and the reason information further indicates an identifier of the Transmission Configuration Indicator (TCI) status associated with the corresponding data transmission in the first data transmission or the second data transmission.

16. The apparatus according to claim 14 or 15, wherein, The degradation of a single link is determined based on at least one of the following: The difference between the first value of the measurement result from the first data transmission and the second value of the measurement result from the second data transmission exceeds a first threshold. The value of the measurement result of the first data transmission or the second data transmission is less than the second threshold, or The block error rate of the first data transmission or the second data transmission is greater than the third threshold.

17. The apparatus according to any one of claims 13-16, wherein, The cause information is included in at least one of the following: Radio resource control message, or Measurement report.

18. The apparatus according to any one of claims 13-17, wherein, The device is such that: The control information is sent to the terminal device, indicating the first Transmission Configuration Indicator (TCI) state for the first data transmission and the second TCI state for the second data transmission.

19. The apparatus according to any one of claims 13-18, wherein, The device is such that: In response to receiving the cause information, further control information indicating the status of a single Transmission Configuration Indicator (TCI) or a pair of TCI statuses is sent to the terminal device.

20. The apparatus according to claim 19, wherein, The device is such that: In response to receiving the cause information, a request is sent to the terminal device for updating a measurement report for the TCI status of at least one of the device or the network device; Receive a measurement report associated with at least one beam used for receiving from the terminal device; The individual TCI state or the pair of TCI states is determined based on the measurement report; as well as Send further control information to the terminal device indicating the single TCI state of the device or the pair of TCI states of the device and the network device.

21. The apparatus according to any one of claims 13-20, wherein, The apparatus includes a first transmission receiving point (TRP), and the network device includes a second TRP.

22. A method comprising: The terminal device receives the first data transmission from the first network device. Receive a second data transmission from a second network device, wherein the first data transmission and the second data transmission are based on the same control information; as well as Send cause information to one of the first network device or the second network device, the cause information indicating the cause of relative link degradation or absolute link degradation associated with at least one of the first data transmission or the second data transmission.

23. A method comprising: Sending a first data transmission from a network device to a terminal device, wherein the first data transmission and a second data transmission are based on the same control information, and the second data transmission is sent from another network device to the terminal device; and The terminal device receives cause information indicating the cause of relative or absolute link degradation associated with at least one of the network devices or the other network device.

24. An apparatus comprising: Components for receiving first data transmission from a first network device; A component for receiving a second data transmission from a second network device, wherein the first data transmission and the second data transmission are based on the same control information; as well as A component for sending cause information to one of the first network device or the second network device, the cause information indicating the cause of relative link degradation or absolute link degradation associated with at least one of the first data transmission or the second data transmission.

25. An apparatus comprising: A component for sending a first data transmission to a terminal device, wherein the first data transmission and the second data transmission are based on the same control information, and the second data transmission is sent from a network device to the terminal device; as well as A component for receiving cause information from the terminal device, the cause information indicating the cause of relative or absolute link degradation associated with at least one of the device or the network device.

26. A computer-readable medium comprising instructions stored thereon, the instructions being configured to cause a device to at least: Receive the first data transmission from the first network device; Receive a second data transmission from a second network device, wherein the first data transmission and the second data transmission are based on the same control information; and Send cause information to one of the first network device or the second network device, the cause information indicating the cause of relative link degradation or absolute link degradation associated with at least one of the first data transmission or the second data transmission.

27. A computer-readable medium comprising instructions stored thereon, the instructions being configured to cause a device to at least: Sending a first data transmission to a terminal device, wherein the first data transmission and a second data transmission are based on the same control information, and the second data transmission is sent from a network device to the terminal device; and Receive cause information from the terminal device, the cause information indicating the cause of relative link degradation or absolute link degradation associated with at least one of the device or the network device.

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